xref: /openbmc/linux/include/drm/drm_mm.h (revision afb46f79)
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2  *
3  * Copyright 2006-2008 Tungsten Graphics, Inc., Cedar Park, TX. USA.
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28 /*
29  * Authors:
30  * Thomas Hellstrom <thomas-at-tungstengraphics-dot-com>
31  */
32 
33 #ifndef _DRM_MM_H_
34 #define _DRM_MM_H_
35 
36 /*
37  * Generic range manager structs
38  */
39 #include <linux/bug.h>
40 #include <linux/kernel.h>
41 #include <linux/list.h>
42 #include <linux/spinlock.h>
43 #ifdef CONFIG_DEBUG_FS
44 #include <linux/seq_file.h>
45 #endif
46 
47 enum drm_mm_search_flags {
48 	DRM_MM_SEARCH_DEFAULT =		0,
49 	DRM_MM_SEARCH_BEST =		1 << 0,
50 	DRM_MM_SEARCH_BELOW =		1 << 1,
51 };
52 
53 enum drm_mm_allocator_flags {
54 	DRM_MM_CREATE_DEFAULT =		0,
55 	DRM_MM_CREATE_TOP =		1 << 0,
56 };
57 
58 #define DRM_MM_BOTTOMUP DRM_MM_SEARCH_DEFAULT, DRM_MM_CREATE_DEFAULT
59 #define DRM_MM_TOPDOWN DRM_MM_SEARCH_BELOW, DRM_MM_CREATE_TOP
60 
61 struct drm_mm_node {
62 	struct list_head node_list;
63 	struct list_head hole_stack;
64 	unsigned hole_follows : 1;
65 	unsigned scanned_block : 1;
66 	unsigned scanned_prev_free : 1;
67 	unsigned scanned_next_free : 1;
68 	unsigned scanned_preceeds_hole : 1;
69 	unsigned allocated : 1;
70 	unsigned long color;
71 	unsigned long start;
72 	unsigned long size;
73 	struct drm_mm *mm;
74 };
75 
76 struct drm_mm {
77 	/* List of all memory nodes that immediately precede a free hole. */
78 	struct list_head hole_stack;
79 	/* head_node.node_list is the list of all memory nodes, ordered
80 	 * according to the (increasing) start address of the memory node. */
81 	struct drm_mm_node head_node;
82 	unsigned int scan_check_range : 1;
83 	unsigned scan_alignment;
84 	unsigned long scan_color;
85 	unsigned long scan_size;
86 	unsigned long scan_hit_start;
87 	unsigned long scan_hit_end;
88 	unsigned scanned_blocks;
89 	unsigned long scan_start;
90 	unsigned long scan_end;
91 	struct drm_mm_node *prev_scanned_node;
92 
93 	void (*color_adjust)(struct drm_mm_node *node, unsigned long color,
94 			     unsigned long *start, unsigned long *end);
95 };
96 
97 /**
98  * drm_mm_node_allocated - checks whether a node is allocated
99  * @node: drm_mm_node to check
100  *
101  * Drivers should use this helpers for proper encapusulation of drm_mm
102  * internals.
103  *
104  * Returns:
105  * True if the @node is allocated.
106  */
107 static inline bool drm_mm_node_allocated(struct drm_mm_node *node)
108 {
109 	return node->allocated;
110 }
111 
112 /**
113  * drm_mm_initialized - checks whether an allocator is initialized
114  * @mm: drm_mm to check
115  *
116  * Drivers should use this helpers for proper encapusulation of drm_mm
117  * internals.
118  *
119  * Returns:
120  * True if the @mm is initialized.
121  */
122 static inline bool drm_mm_initialized(struct drm_mm *mm)
123 {
124 	return mm->hole_stack.next;
125 }
126 
127 static inline unsigned long __drm_mm_hole_node_start(struct drm_mm_node *hole_node)
128 {
129 	return hole_node->start + hole_node->size;
130 }
131 
132 /**
133  * drm_mm_hole_node_start - computes the start of the hole following @node
134  * @hole_node: drm_mm_node which implicitly tracks the following hole
135  *
136  * This is useful for driver-sepific debug dumpers. Otherwise drivers should not
137  * inspect holes themselves. Drivers must check first whether a hole indeed
138  * follows by looking at node->hole_follows.
139  *
140  * Returns:
141  * Start of the subsequent hole.
142  */
143 static inline unsigned long drm_mm_hole_node_start(struct drm_mm_node *hole_node)
144 {
145 	BUG_ON(!hole_node->hole_follows);
146 	return __drm_mm_hole_node_start(hole_node);
147 }
148 
149 static inline unsigned long __drm_mm_hole_node_end(struct drm_mm_node *hole_node)
150 {
151 	return list_entry(hole_node->node_list.next,
152 			  struct drm_mm_node, node_list)->start;
153 }
154 
155 /**
156  * drm_mm_hole_node_end - computes the end of the hole following @node
157  * @hole_node: drm_mm_node which implicitly tracks the following hole
158  *
159  * This is useful for driver-sepific debug dumpers. Otherwise drivers should not
160  * inspect holes themselves. Drivers must check first whether a hole indeed
161  * follows by looking at node->hole_follows.
162  *
163  * Returns:
164  * End of the subsequent hole.
165  */
166 static inline unsigned long drm_mm_hole_node_end(struct drm_mm_node *hole_node)
167 {
168 	return __drm_mm_hole_node_end(hole_node);
169 }
170 
171 /**
172  * drm_mm_for_each_node - iterator to walk over all allocated nodes
173  * @entry: drm_mm_node structure to assign to in each iteration step
174  * @mm: drm_mm allocator to walk
175  *
176  * This iterator walks over all nodes in the range allocator. It is implemented
177  * with list_for_each, so not save against removal of elements.
178  */
179 #define drm_mm_for_each_node(entry, mm) list_for_each_entry(entry, \
180 						&(mm)->head_node.node_list, \
181 						node_list)
182 
183 /**
184  * drm_mm_for_each_hole - iterator to walk over all holes
185  * @entry: drm_mm_node used internally to track progress
186  * @mm: drm_mm allocator to walk
187  * @hole_start: ulong variable to assign the hole start to on each iteration
188  * @hole_end: ulong variable to assign the hole end to on each iteration
189  *
190  * This iterator walks over all holes in the range allocator. It is implemented
191  * with list_for_each, so not save against removal of elements. @entry is used
192  * internally and will not reflect a real drm_mm_node for the very first hole.
193  * Hence users of this iterator may not access it.
194  *
195  * Implementation Note:
196  * We need to inline list_for_each_entry in order to be able to set hole_start
197  * and hole_end on each iteration while keeping the macro sane.
198  *
199  * The __drm_mm_for_each_hole version is similar, but with added support for
200  * going backwards.
201  */
202 #define drm_mm_for_each_hole(entry, mm, hole_start, hole_end) \
203 	for (entry = list_entry((mm)->hole_stack.next, struct drm_mm_node, hole_stack); \
204 	     &entry->hole_stack != &(mm)->hole_stack ? \
205 	     hole_start = drm_mm_hole_node_start(entry), \
206 	     hole_end = drm_mm_hole_node_end(entry), \
207 	     1 : 0; \
208 	     entry = list_entry(entry->hole_stack.next, struct drm_mm_node, hole_stack))
209 
210 #define __drm_mm_for_each_hole(entry, mm, hole_start, hole_end, backwards) \
211 	for (entry = list_entry((backwards) ? (mm)->hole_stack.prev : (mm)->hole_stack.next, struct drm_mm_node, hole_stack); \
212 	     &entry->hole_stack != &(mm)->hole_stack ? \
213 	     hole_start = drm_mm_hole_node_start(entry), \
214 	     hole_end = drm_mm_hole_node_end(entry), \
215 	     1 : 0; \
216 	     entry = list_entry((backwards) ? entry->hole_stack.prev : entry->hole_stack.next, struct drm_mm_node, hole_stack))
217 
218 /*
219  * Basic range manager support (drm_mm.c)
220  */
221 int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node);
222 
223 int drm_mm_insert_node_generic(struct drm_mm *mm,
224 			       struct drm_mm_node *node,
225 			       unsigned long size,
226 			       unsigned alignment,
227 			       unsigned long color,
228 			       enum drm_mm_search_flags sflags,
229 			       enum drm_mm_allocator_flags aflags);
230 /**
231  * drm_mm_insert_node - search for space and insert @node
232  * @mm: drm_mm to allocate from
233  * @node: preallocate node to insert
234  * @size: size of the allocation
235  * @alignment: alignment of the allocation
236  * @flags: flags to fine-tune the allocation
237  *
238  * This is a simplified version of drm_mm_insert_node_generic() with @color set
239  * to 0.
240  *
241  * The preallocated node must be cleared to 0.
242  *
243  * Returns:
244  * 0 on success, -ENOSPC if there's no suitable hole.
245  */
246 static inline int drm_mm_insert_node(struct drm_mm *mm,
247 				     struct drm_mm_node *node,
248 				     unsigned long size,
249 				     unsigned alignment,
250 				     enum drm_mm_search_flags flags)
251 {
252 	return drm_mm_insert_node_generic(mm, node, size, alignment, 0, flags,
253 					  DRM_MM_CREATE_DEFAULT);
254 }
255 
256 int drm_mm_insert_node_in_range_generic(struct drm_mm *mm,
257 					struct drm_mm_node *node,
258 					unsigned long size,
259 					unsigned alignment,
260 					unsigned long color,
261 					unsigned long start,
262 					unsigned long end,
263 					enum drm_mm_search_flags sflags,
264 					enum drm_mm_allocator_flags aflags);
265 /**
266  * drm_mm_insert_node_in_range - ranged search for space and insert @node
267  * @mm: drm_mm to allocate from
268  * @node: preallocate node to insert
269  * @size: size of the allocation
270  * @alignment: alignment of the allocation
271  * @start: start of the allowed range for this node
272  * @end: end of the allowed range for this node
273  * @flags: flags to fine-tune the allocation
274  *
275  * This is a simplified version of drm_mm_insert_node_in_range_generic() with
276  * @color set to 0.
277  *
278  * The preallocated node must be cleared to 0.
279  *
280  * Returns:
281  * 0 on success, -ENOSPC if there's no suitable hole.
282  */
283 static inline int drm_mm_insert_node_in_range(struct drm_mm *mm,
284 					      struct drm_mm_node *node,
285 					      unsigned long size,
286 					      unsigned alignment,
287 					      unsigned long start,
288 					      unsigned long end,
289 					      enum drm_mm_search_flags flags)
290 {
291 	return drm_mm_insert_node_in_range_generic(mm, node, size, alignment,
292 						   0, start, end, flags,
293 						   DRM_MM_CREATE_DEFAULT);
294 }
295 
296 void drm_mm_remove_node(struct drm_mm_node *node);
297 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new);
298 void drm_mm_init(struct drm_mm *mm,
299 		 unsigned long start,
300 		 unsigned long size);
301 void drm_mm_takedown(struct drm_mm *mm);
302 bool drm_mm_clean(struct drm_mm *mm);
303 
304 void drm_mm_init_scan(struct drm_mm *mm,
305 		      unsigned long size,
306 		      unsigned alignment,
307 		      unsigned long color);
308 void drm_mm_init_scan_with_range(struct drm_mm *mm,
309 				 unsigned long size,
310 				 unsigned alignment,
311 				 unsigned long color,
312 				 unsigned long start,
313 				 unsigned long end);
314 bool drm_mm_scan_add_block(struct drm_mm_node *node);
315 bool drm_mm_scan_remove_block(struct drm_mm_node *node);
316 
317 void drm_mm_debug_table(struct drm_mm *mm, const char *prefix);
318 #ifdef CONFIG_DEBUG_FS
319 int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm);
320 #endif
321 
322 #endif
323